I've a 42A Oppy Briggs, stock carb, and I'd like to have a whiz-bang, snazzy racer air cleaner for it....velocity stack, or something. Have you any advice on specific items and where to get them? Thanks.

Order the velocity stack from EC. Take a half-round file and smooth the top of the air horn of the carburetor. find some screws to work , as you will find they are not quite on-center. That's because the velocity stack is made for a Tillotson carb, but it will work just fine. You are going to have to change the float bowl vent location as well.

You really, really really really really need to get George to build you a carb. It's worth the money. You will NOT be disappointed. Oppys need lots of air.

EC has a nice "universal" air cleaner, one with chrome top, one without. I don't remember the part numbers.

My fave is a K&N chrome-top, P/N F028h6. You will have to get some straight hose down at your NAPA store and make an adapter ring to go between the outside edge of the velocity stack and the air filter.

The second one can have some hood clearance issues depending on your hood, but if you have your engine sideways, and trim the hood, it looks pretty sharp poking out of the side.